Here are some of the most important questions that will be answered by voters today:

How strong is anti-establishment feeling among Northeastern Republicans?

So far, establishment favorites have fallen in Texas, Kentucky, Florida, Utah and Nevada, but we haven't had a test of the GOP primary electorate in the more moderate political climates of the Northeast. We will learn a lot in a hurry. In Democratic-leaning Delaware, the state's moderate congressman, Mike Castle, is trying to turn back an aggressive challenge from conservative marketing consultant Christine O'Donnell. In Maryland, the establishment's choice for governor, former Gov. Bob Ehrlich, faces underfunded but enthusiastic conservative Brian Murphy. And in New Hampshire, Attorney General Kelly Ayotte finds herself squeezed between a moderate businessman and a conservative Republican activist.

If any of the establishment favorites fall, it would put an exclamation point on a GOP primary season dominated by the party's right wing.

Candidates backed by the former Alaska governor have won more than 80 percent of their primaries. But Palin hasn't been tested in the Northeast. Palin is backing underdog conservatives O'Donnell in Delaware and Murphy in Maryland. But she backs Ayotte in the Granite State. If O'Donnell shocks Castle in Delaware, Palin will get a lot of credit.

What happens when the tea party is divided?

That's the case in both Delaware and New Hampshire. In New Hampshire, Palin is backing Ayotte while some other tea party factions and the influential Manchester Union Leader newspaper are backing the most conservative candidate in the race, Ovide Lamontagne. In Delaware, Palin is backing O'Donnell while the grassroots group FreedomWorks is staying neutral.

"We've stayed out of that race because we're not convinced that Christine O'Donnell can win," said FreedomWorks President Matt Kibbe.

Four years ago, Washington Mayor Adrian Fenty was the toast of the Democratic Party. An energetic 36-year-old reformer, he promised to weed out corruption in the city government and clean up a school system considered by many education experts to be the nation's worst. But capital city voters seem more concerned about Fenty's abrasive personality than his public record. Polls show him trailing 67-year-old D.C. council chairman Vincent Gray.

Can Democrats lose another Kennedy seat?

First it was the Massachusetts Senate seat represented by the late Ted Kennedy and captured in a special election by Republican Scott Brown. Now, it's the Rhode Island House seat being surrendered by his son, Patrick, who decided earlier this year to retire from Congress at age 43. The Democratic primary has been messy. Opponents have called the Democratic frontrunner, Providence Mayor David Cicilline, dishonest and incompetent. Businessman Anthony Gemma calls him "possibly the most ineffective mayor in the city's history." The opposition is split, with former Democratic state party chairman Bill Lynch appealing for blue-collar support and state Rep. David Segal attracting liberal votes.